I do not understand what you want me to solve.
Answer:
0.0537
Step-by-step explanation:
This follows a binomial distribution with : n
Number of trials 'N' = 12 ; Probability of success (difference between speakers) 'p' = 1/2 or 0.5 ; Probability of failure (no difference b/w speakers) = 1/2 or 0.5 ; No of success 'r' = 3
P (X = 3) = 
= 12C3 (0.5)^3 (0.5)^9
0.0537
4 (x-3)=3x-4
4x-12=3x-4
4x-12-3x=3x-4-3x
x-12=-4
x-12+12=-4+12
x=8
No, because 2 numbers multiplied by each other will not make 26.
Hope this helped ;)